Source : Webster's Revised Unabridged Dictionary (1913)

Deduction \De*duc"tion\, n. [L. deductio: cf. F. d['e]duction.]
   1. Act or process of deducing or inferring.

            The deduction of one language from another.
                                                  --Johnson.

            This process, by which from two statements we deduce
            a third, is called deduction.         --J. R. Seely.

   2. Act of deducting or taking away; subtraction; as, the
      deduction of the subtrahend from the minuend.

   3. That which is deduced or drawn from premises by a process
      of reasoning; an inference; a conclusion.

            Make fair deductions; see to what they mount.
                                                  --Pope.

   4. That which is deducted; the part taken away; abatement;
      as, a deduction from the yearly rent.

   Syn: See {Induction}.

Source : WordNet®

deduction
     n 1: a reduction in the gross amount on which a tax is
          calculated; reduces taxes by the percentage fixed for
          the taxpayer's income bracket [syn: {tax write-off}, {tax
          deduction}]
     2: an amount or percentage deducted [syn: {discount}]
     3: something that is inferred (deduced or entailed or implied);
        "his resignation had political implications" [syn: {entailment},
         {implication}]
     4: reasoning from the general to the particular (or from cause
        to effect) [syn: {deductive reasoning}, {synthesis}]
     5: the act of subtracting (removing a part from the whole); "he
        complained about the subtraction of money from their
        paychecks" [syn: {subtraction}] [ant: {addition}]
     6: the act of reducing the selling price of merchandise [syn: {discount},
         {price reduction}]